Process for the continuous control of homogenization of a mixture of two or more materials

ABSTRACT

A PROCESS FOR THE CONTINUOUS CONTROL OF HOMOGENIZATION OF A MIXTURE OF TWO OR MORE MATERIALS. THERE IS ADDED TO A MIXTURE A SMALL AMOUNT OF A MAGNETICALLY ORIENTATED INDICATOR MATERIAL IN POWDER FORM. THIS INDICATOR MATERIAL IS DISPERSED INTO THE MIXTURE BY THE HOMOGENIZATOR. ONE OR MORE INSTRUMENTS ARE MOUNTED IN THE HOMOGENIZATOR FOR MEASURING THE MAGNETIC FIELD INTENSITY OF THE MIXTURE. UPON THE RECEIVING OF AN EVEN SIGNAL FROM THE MEASURING INSTRUMENT, THE HOMOGENIZATION PROCESS OF THE MIXTURE IS COMPLETED.

United States Patent PROCESS FOR THE CONTINUOUS CONTROL OF HOMOGENIZATION OF A MIXTURE OF TWO OR MORE MATERIALS Zdenek Severa, Prague, and Antonin Benda and Petr Vachalovsky, Roztoky, Czechoslovakia, assiguors to Spofa, United Pharmaceutical Works, Prague, Czechoslovakia N0 Drawing. Filed Mar. 12, 1969, Ser. No. 806,716

Int. Cl. B011? 3/00 US. Cl. 259-1R 2 Claims ABSTRACT OF THE DISCLOSURE A process for the continuous control of homogenization of a mixture of two or more materials. There is added to a mixture a small amount of a magnetically orientated indicator material in powder form. This indicator material is dispersed into the mixture by the homogenizator. One or more instruments are mounted in the homogenizator for measuring the magnetic field intensity of the mixture. Upon the receiving of an even signal from the measuring instrument, the homogenization process of the mixture is completed.

The present invention relates generally to a method for continuously controlling the homogenization of mixtures composed of two or more substances.

One of the well-known methods used for homogenizing mixtures consisting of several substances presents some very important disadvantages, especially insofar as the control of the degree of homogeneity is concerned. This degree of homogeneity conditions the quality of the end product, especially when two substances of widely varying specific weights are to be homogenized. Homogenizing machines are generally constructed for the particular operation for which they are used. In order to rigorously control the homogeneity in these known homogenizing machines, it is necessary to take samples of the mixture which is to be homogenized during the homogenizing process. The taking of such samples, however, requires the turning off of the homogenizing machine, which lengthens the time required for completing the homogenization and also limits the capacity of the installation itself. After the samples have been taken and analysed, the time for completing the homogenization of a particular mixture is empirically determined, based on preset conditions in a particular installation. The aforedescribed known process has further disadvantages in requiring that the finished product, which constitutes the homogenized mixture, has again to be analysed by taking at least two samples from the mass of the mixture from two volume parts thereof which should be spaced as much as possible from each other. This requires, however, that the whole mixture mass remains stored in the homogenizer until the analysis thereof is completed, thereby causing a considerable waste of time and also the wasteful use of the storage and manipulation spaces of the installation.

3,606,261 Patented Sept. 20, 1971 ice Considerable research work has been undertaken in recent times to provide a method which overcomes the aforedescribed disadvantages. These more recently developed methods are based on the same principle, namely that when two substances are mixed in different ratios but having about the same specific weights, homogeneity of the mixture is achieved at the moment when the particles of a substance, a small quantity of which is only added to the mixture, has been evenly distributed among the other substances of the mixture. Taking ad vantage of this phenomenon, the more recently developed methods for homogenizing two or more substances have simplified the homogenization control by requiring only the analysis of one indicator substance within the mixture to be homogenized. Thus the more recently developed methods utilize an indicator substance which is only added in a small proportion to the mixture and which can be easily determined and analysed. However, these more recently developed methods still require, in order to ascertain the degree of homogeneity of the mixture, that samples be taken from various parts of the mixture. The degree of homogeneity is then determined by analysing the degree of dispersion of the indicator substance in the taken samples. In this manner it is possible to control the homogeneity of a mixture relatively fast by adding to the mixture sodium chloride and thereafter determining the chlorine content of a sample taken from the mixture. Similarly it is possible to determine the homogeneity of the mixture by adding an appropriate color-indicator substance an thereafter determining the degree of homogeneity colorimetrically.

However, the aforedescribed recently developed known methods for controlling the homogenization of a mixture require that certain limiting conditions be met in order to successfully carry out the method. Thus the mixture must not contain any substance which is not suitable for the aforedescribed controlling method and also the substances of the mixture must not chemically react with one of the components thereof. Even When these conditions are met, the aforedescribed known methods do not ensure the optimal use of the equipment involved because the methods still are based on the evaluation of empirical data which, as a general rule, takes longer than necessary.

It is a general object of this invention to provide a method for controlling the homogenization process of a mixture consisting of two or more substances in which the aforedescribed disadvantages have been eliminated. In the process of this invention, a magnetically orientated substance in powdered form is added as an indicator material to the mixture. This indicator material is then dispersed in the mixture and the dispersed indicator material then produces a magnetic field in the mixture which is measured by at least one instrument mounted in the homogenizer for measuring the intensity of the magnetic field produced by the indicator material. When an even signal is received by the measuring instrument, the homogenization process is completed. Ferrite in powdered form is preferably used as a magnetically oriented additive. However, other suitable powdered materials may also be used.

When the process of this invention is correctly carried out, the magnetically orientated powdered indicator material, which is dispersed in the mixture, indicates by means of the magnetic field intensity measured by the instrument in the homogenizer, the instantaneous state of homogeneity of the mixture itself without requiring the taking of samples and the analysis thereof. Thus it is possible to register the indicated state of homogenization of the mixture in a suitable container by means of one or more magnetic field intensity measuring instruments which are mounted within the homogenizer. The instant at which the measurements of the various instruments indicate the same values, the homogenization process of the mixture has been completed. Suitable electrochemical means may be provided and may be operatively connected to the actuating motor of the homogenizer, which, when receiving an appropriate signal from the measuring instruments, stop the actuating motor of the homogenizer, and automatically evacuate the homogenized mixture therefrom. Furthermore, it is possible to graphically illustrate the progress of the homogenization process of the mixture, and the graph obtained during the process may then be used as a control means.

The process in accordange with this invention makes possible a complete control of the course of the homogenization process and provides for an economic automhereinafter described, can be better understood and carried into practice, it will now be described by several examples which are not intended to specifically define or limit the invention.

EXAMPLE 1 In a homogenizer made out of stainless steel the following mixture is placed:

Chlorotetracyclinekilograms Vitamin A--1 billion I.U. Vitamin D 2,OO0.000 I.U. Vitamin B 1 kilogram Sodium salicylate200 kilograms Magnetically orientated hardened ferrite powder-5 kilograms Feed fiourup to 1000 kilograms An instrument for detecting the intensity of the varying magnetic field of the mixture is mounted within the homogenizer, preferably in the area where the main movement of the mixture occurs within the homogenizer. After the homogenizer has been activated, there are detected the alternating currents in the instrument by means of an amplifier having a sensitivity of at least 5 microvolts. As long as the mixture in the homogenizer has not reached full homogeneity, the alternating current emitted by the instrument continues to vary. A reproducer is operatively connected to the instrument and serves to control the orientation of the amplified signals being emitted by the instrument. This reproducer preferably takes the form of an integrator, which transforms the output alternating signal into signals having house current voltage, which is proportional to the intensity of the alternating frequency that forms as the ferrite powder particles slide by the detecting instrument in the homogenizer. The homogenization process is completed when a so-called uniform noise appears at the output of the control circuit.

4 EXAMPLE 2 In a homogenizer built of stainless steel the following mixture is inserted:

Kilograms Vitamin E 1 Nicotinic acid 1 Calcium pentohenate 0.5 Betaine hydrochloride 25 Methionine 25 Hydroquinone 15 Choline chloride 25 Acetylaminonitrothiazol 15 Sulfachinoxaline 12.5 Manganese sulfate 4 Ferrite in powder form 5 Feed flour Up to 1000 The homogenizer is provided with three detecting instruments which determine the intensity of the varying magnetic field within the mixture. These detecting instruments are uniformly switched over to the amplifier, and thereby it is possible to control the homogenization process by ascertaining when all three detectors emit the same signal, that is after the integration, have the same voltage. When a registration device is used, the coincidence of all curves into one curve establishes the completion of the homogenization process. At the moment that the coincidence of the three curves occurs, the homogenization process of the mixture is attained and the homogenizator is automatically switched off.

The method of this invention has been described hereinabove in preferred embodiments, but it is to be understood that the invention is in no way confined to the particular forms, uses, or sizes shown and described, the same being merely elucidative, and that the method of the invention can be made and carried out in other ways without departure from the spirit of the invention, and therefore there is claimed the right to employ all equivalents coming within the scope of the appended claims and by means of which the objects of the invention are obtained and new advantagm and results accomplished.

What we claim is:

1. A process for continuously controlling the homogenization of a mixture of two or more substances, comprising the steps of I adding an indicator material in the form of a magnetically oriented powder to said mixture, mechanically homogenizing said mixture containing said indicator material, thereby gradually dispersing said indicator material in said mixture, and determining the degree of dispersion of said indicator material in said mixture by means of at least one magnetic field intensity monitoring instrument, wherein when an even signal is attained by said instrument, the homogenization process of said mixture is completed.

2. The process for continuously controlling the homogenization of a mixture of two or more substances as set forth in claim 1, wherein said magnetically oriented powder is magnetized powdered ferrite.

References Cited UNITED STATES PATENTS 3,219,318 11/1965 Hershler 2591 3,448,375 6/1969 Meunier 324-34 ROBERT W. JENKINS, Primary Examiner 

